Telephone switching offices and companies using a large number of communication devices such as modems, telephones, facsimile machines and the like are all faced with the problem of interconnecting these devices with electrical and/or optical cables. Such cables frequently reside within ducts or troughs that contain a large number of similar cables. Each cable terminates in a plug to facilitate the interconnection process. As devices are replaced, or as new interconnections are required, these cables need to be removed from the duct and replaced by others. And while adding cables to a duct is not a particularly difficult task, removing them is. Indeed, removal is accomplished by disconnecting the plug from the communication device and pulling it backwards (i.e., by its associated cable) through the duct. Since it is not desirable to sever the plug from the cable, the plug needs to be streamlined in order to avoid snagging other cables as it is pulled. Imagine, for example, the difficulty associated with pulling a plug, shaped like a fishhook, through a maze of wires; and yet the most popular plug used in the communication industry is shaped that way. (Perhaps the most widely used and accepted are know as "RJ-type" plugs which are used on all telephones and disclosed in numerous patents including U.S. Pat. No. 3,860,316 to Edwin C. Hardesty.) These plugs have achieved overwhelming acceptance by customers because they are inexpensive, reliable, and their operation is intuitively understood.
RJ-type plugs include a locking tab (hereinafter "cantilever latch" or "latch") for interlocking with an associated jack; but the latch snags other wires and cables when being pulled backwards through a concentrated area of wires and cables as though it were designed for this nefarious purpose. This difficulty is exacerbated by the fact that the use of such modular plugs is growing (such plugs are now designed to accommodate high speed electrical data communication). Today, even optical plugs are being designed in this same general style.
To some extent, the "snagging" problem has been overcome by incorporating a pair of sloped sidewalls at the back end of the plug. This feature is commercially available from AT&T in its "Snagless RJ-45 Plug," and is incidentally shown in U.S. Pat. No. 4,611,875. However, such sidewalls need to be taller than the free end of the latch which must be deflected downward in order to release the plug from an associated receptacle. These sidewalls are relatively close together and it is difficult to manually deflect the latch because there is little room for a user's finger. As the desire for greater connection density grows, particularly in telephone connecting panels, future plugs will need to be smaller and sidewalls will unacceptably interfere with the customer's ability to operate the plug.
Sidewalls have also been adapted for use in optical connectors--one of which is shown in U.S. Pat. No. 5,224,186. In this optical connector, the sidewalls appear to be part of the fixed end of the cantilever latch itself, so the user's finger doesn't need to be inserted between the sidewalls. However, this style of connector is undesirable for other reasons. Because the fixed end of the cantilever latch is located at the cable-entrance end of the plug, the mechanical advantage associated with the cantilever is exactly opposite the desired mechanical advantage. That is, the user is required to exert a relatively large actuating force near the fixed end of the cantilever in order to deliver a relatively small latching force at its free end.
What is needed and, seemingly, what is unavailable in the prior art, is a connector for terminating an electrical or optical cable that resists snagging when it is pulled backwards through a concentrated area of wires and cables. Desirably, this connector should be inexpensive to manufacture and be easy to manually operate when miniaturized in size. Moreover, this connector should remain easy to manually operate when installed in a dense array (i.e., side-by-side) of similar connectors.